Cyperus giganteus |
Cyperus lancastriensis |
|
---|---|---|
giant flatsedge, Mexican papyrus |
manyflower flatsedge, Porter's sedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
basally cormlike, trigonous, (10–)20–80 cm × 1–3 mm, glabrous. |
Leaves | bladeless. |
inversely W-shaped, 20–70 cm × 5–11 mm, adaxial surface, margins minutely scabridulous. |
Inflorescences | spikes loosely cylindric, 15–40 × 8–16 mm; rays 5–8, ascending to erect, stiff,20–30 cm; 2d order rays 5–15 cm; bracts 10–12, ascending at 30–60°, flat, (8–) 20–45 cm × 4–12 mm; 2d order bracts (5–)15–25 cm × 1.5–5 mm; rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 mm wide. |
spikes densely ellipsoid to obovoid, 2.5–4.3 × 1.5–3 cm; rays 5–10, 4–20 cm, glabrous; rachis 7–14 mm; bracts 3–8, horizontal to ascending at 45°, flat, 5–35 cm × 2.5–6 mm; rachilla persistent, wings 0.5 mm wide. |
Spikelets | (15–)50–80, slightly compressed, linear, ± quadrangular, 5–12 × 0.6–1.4 mm; floral scales 8–20, appressed, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse. |
50–90, linear-lanceoloid to linear-subulate, ± terete-quadrangular, (11–)12–13(–15) × 1.1–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 3–6(–8), appressed, whitish green or often yellow-tinted, sometimes reddish striate, laterally 4-ribbed, ovate-lanceolate, (3.9–)4.2–4.6(–4.8) × 1.6–2 mm. |
Flowers | anthers 0.7–1 mm (connective prolonged beyond anther as red subulate appendage 0.2–0.5 mm, its apex sometimes setose); styles 0.2–0.5 mm; stigmas (0.8–)1.2–1.8 mm. |
anthers 0.7–1 mm; styles 1–1.5 mm; stigmas 2–3 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
yellowish brown to brown, ± stipitate, conspicuously falcate, 3–4 times long as wide, oblong, 2.2–2.6 × 0.6–0.7 mm, apex obtuse, surfaces puncticulate. |
Cyperus giganteus |
Cyperus lancastriensis |
|
Phenology | Fruiting summer. | Fruiting summer (Jul–Aug). |
Habitat | Stream banks, marshes | Disturbed, sunny or partly shaded places in mesic or dry-mesic soils, often on riverbanks and flood plains |
Elevation | 0–10 m (0–0 ft) | 0–800 m (0–2600 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
AL; AR; DC; DE; FL; GA; KY; MD; MO; NC; NJ; OH; PA; SC; TN; VA; WV
|
Discussion | Cyperus giganteus was erroneously reported from Florida, a misidentification of C. papyrus (R. R. Haynes and A. Lasseigne 1969). Recently, some nurseries specializing in water plants have begun to offer C. giganteus under the name “Mexican papyrus.” Escaped cultivated plants may be expected in southeastern and southwestern United States. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 173. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. refractus var. lancastriensis, Mariscus lancastriensis | |
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | Porter: in A. Gray, Manual ed. 5 issue 6, 555. (1867) |
Web links |